As a technique for improving throughput degradation due to inter-cell interference, adaptive FFR is proposed. In the adaptive FFR, a transmission use band is divided into the high power transmission band and the low power transmission band. In the low transmission band, transmission power is variable in a stepwise manner, and the mode to support each stage is provided (see FIG. 1).
In a wireless communication system adopting this adaptive FFR, a base station (NB) selects a mode based on an interference report transmitted from a wireless terminal (UE), sets the transmission power associated with this selected mode and then performs downlink transmission. Afterward, it is reported to an adjacent NB that the mode was changed, and, in response to this, the adjacent NB changes the mode. Here, increasing the mode number is equivalent to lowering a reuse factor.
Thus, it is possible to remove interference between adjacent cells and improve throughput.
Non-Patent Document 1: LTE contribution [3GPP TSG-RAN WG1 R1-071449 (Nortel)]